Wiping articles

ABSTRACT

An article for the wet/damp wiping of surfaces comprises a moisture-absorbing wipe that provides at least one surface of the article, the wipe comprising bamboo fibres. The wipe may be formed from a textile material and contains at least 10%, preferably at least 30%, by weight of bamboo fibres.

The present invention relates to articles for use in wiping surfaces. In particular, the invention is concerned with wiping articles intended to be used in such a way that they are likely to be in a wet or damp condition for a prolonged period of time. The invention is concerned more especially, but not exclusively, with wiping articles of that type intended for use in wiping hard surfaces in the domestic environment, for example the surfaces of kitchen and bathroom furniture and appliances.

Wiping articles in a form known as “wipes” are widely used by consumers in various environments, including domestic, industrial, hospital and food industry environments, for wiping surfaces such as work surfaces and floors. As used herein, the term “wipe” means a piece of web material the characteristics of which are such that it is effective per se for the wiping of a surface (i.e. it can be handled and used to wipe a surface without; for example, being layered with, or laminated to, another material) with both surfaces of the web material providing a wiping action. Many different types of wipe are currently available, ranging from paper towels to textile dish cloths and floor cloths.

The type of web material used for a wipe depends on the cleaning/wiping function that the wipe is required to perform, and its intended lifetime. Some wipes are intended to be used dry (for example, paper towels that are used to mop-up spilt liquid) and others are intended to be used in a damp or wet condition. Wipes can be categorized, depending on their durability, as “disposable” (meaning that the wipe is intended to be discarded immediately after use), “semi-disposable” (meaning that that the wipe can be washed and re-used a limited number of times), or “reusable” (meaning that the wipe is intended to be washed and re-used for an indefinite number of times, depending on the use to which it is subjected). A desirable characteristic of certain wipe materials, intended to be used in a damp condition, is a low “wipeability” measurement (an indication of the time that a wet surface takes to dry after it has been wiped with the damp material). Another desirable characteristic of certain wipe materials is a short “drying time (i.e. the ability to dry comparatively quickly after being used in a damp/wet condition).

Examples of web materials that are currently used for wipes include: spun-bond non-woven materials for wipes in the “disposable” category, spun-lace non-woven materials for wipes in the “disposable” and “semi-disposable” categories; and knitted, woven, and thermo-bonded non-woven materials for wipes in the “reusable” category.

A problem frequently reported by consumers is that wipes in the “semi-disposable” and “reusable” categories, intended to be used in the domestic environment in a damp or wet condition, can develop an unhygienic appearance in the form of unpleasant odours and an unpleasant, slimy feel although the wipe itself is otherwise still in a good condition.

Consumers attempt to address this problem themselves by leaving wipes to dry out as much as possible between uses (although the opportunities for this are often very limited because the articles are generally in constant use) or by rinsing them in a chemical such as bleach so that they retain as hygienic an appearance as possible during their lifetime. Increasingly, however, consumers have environmental concerns about the use of such chemicals and would prefer, if possible, to avoid using them. They also find that they have less time available to spend on restoring the condition of wipes and, despite the cost considerations, will resort to throwing them away before the end of their life because they have developed an unpleasant smell and/or feel.

It is known for manufacturers to impregnate cleaning articles with biocides (for example, quaternary ammonium salts) or other chemicals, primarily to treat the surfaces that are being wiped and/or to inhibit the transfer of bacterial infections by the cleaning article. Wipes that have been treated in this way have had limited success in addressing the consumer requirement, described above, that a wipe should retain an hygienic appearance (in terms of smell and feel) throughout its useful life: in some cases, the lack of success has been due to environmental concerns associated with biocidal/chemical treatments and, in other cases, the treatments simply have not produced the effect that the consumer desires.

Cleaning articles impregnated with biocides are described, for example, in EP-A-0 869 216; WO 94/12034; EP-A-358 572 and U.S. Pat. No. 3,018,192.

It is also known to include a biocide in cleaning articles that are packaged in a moist condition. Disposable impregnated wipes, for example, are packaged in a “wet” condition so that they are available for immediate use, and may be treated with a biocide to inhibit the growth of moulds within the package. The presence of these biocides can also be a concern to customers, for environmental reasons.

The present invention is concerned generally with improving the performance of wipes, particularly moisture-absorbing wipes intended for the wet/damp wiping of surfaces. More especially, the present invention is concerned with the provision of a moisture-absorbing wipe intended for wet/damp wiping of surfaces that is less likely to develop an unhygienic appearance in the form of an unpleasant smell or feel if left in a wet or damp condition (either in use, or in a package prior to use) without the need for special treatment(s). The wipe may be used per se as an article for the wet/damp wiping of surfaces, or may be bonded to another material so that it provides a wiping surface of such an article.

The present invention provides an article for the wet/damp wiping of surfaces, the article comprising a moisture-absorbing wipe that provides at least one surface of the article, wherein the wipe comprises bamboo fibres.

It has been found that the inclusion of bamboo fibres in the material from which a moisture-absorbing wipe is formed can increase the length of time for which the wipe will retain an hygienic appearance if left in a wet or damp condition. It has also been noted that the inclusion of bamboo fibres can provide certain wipes with a resistance to bacterial contamination and a degree of bacteriostatic activity, particularly with regard to Salmonella typhimurium. It has further been noted that the inclusion of bamboo fibres can improve the “wipeability” of certain wipes, and the “drying time” of certain wipes. The use of bamboo fibres in textiles is already known and, in the case of textiles intended for use in clothing, towels, and medical dressings, it has already been recognized that the inclusion of bamboo fibres can result in improved moisture-absorbing and anti-bacterial properties (see, for example, WO 2005/068697 and JP-A-2001/115347).

It has also been proposed, in CN-A-1446515, to use bamboo fibres in a cleaning cloth of a traditional type with a view to reducing the transmission, by such a cloth, of potentially lethal bacterial infections such as MRSA and E. Coli. The cloth comprises multiple pieces of material that are layered together to provide the desired characteristics of the cloth: none of the layers of material is effective per se for the wiping of a surface with both surfaces of the material providing a wiping action.

It has not previously been recognized that bamboo fibres can also be used to prevent the development of unpleasant odours and an unpleasant, slimy feel in wipes intended for the wet/damp cleaning of surfaces. More specifically, it has not previously been recognized that a wipe that is frequently, or almost constantly, in a wet/damp condition will be less likely to develop an unpleasant odour and/or feel if it incorporates bamboo fibres.

In an article in accordance with the invention, the moisture-absorbing wipe may be formed from a textile material which can be of any construction known to be suitable for wipes including non-woven, woven and knitted constructions. For the manufacture of suitable woven or knitted materials, the bamboo fibres would first be spun (or otherwise formed) into a continuous yarn whereas, for the manufacture of suitable non-woven web materials, staple or cut bamboo fibres would typically be used. The bamboo fibres could be present in the web materials in combination with fibres (including microfibres) of other materials.

A non-woven material used for the moisture-absorbing wipe can be of any construction known to be suitable for wipes including, for example, spun lace materials; carded, cross-lapped and needle-tacked materials; and thermo-bonded materials. The non-woven material may be latex-coated, and may comprise micro-fibres.

The non-woven material may comprise 100% bamboo fibres especially if, for example, the web material is of spun-bond construction or is reinforced by needle-tacking or stitching with bamboo fibres. Otherwise, a non-woven material comprising 100% bamboo fibres may be reinforced by the provision of a coating, for example a latex coating, on both sides of the material. Alternatively, a thermo-bonded material, in which thermo-bonding fibres are included with the bamboo fibres, may be used. The non-woven material may alternatively comprise a mixture of bamboo and other fibres or microfibres. In that case, the fibre-content of the material preferably comprises at least 10% bamboo fibres by weight. The other fibres/microfibres may be of any type known to be suitable for use in wipes including, for example, other natural fibres or fibres/microfibres of viscose, polyester, polyamide, polypropylene, polyvinyl alcohol or mixtures thereof. Polyester fibres could be included, for example, to reduce costs and to increase the abrasion resistance of the non-woven material if required. A non-woven material comprising a mixture of fibres may also be reinforced by needle-tacking or stitching, by the provision of a coating, for example a latex coating, on both sides of the material, and/or by the inclusion of thermo-bonding fibres.

The non-woven material may have a basis weight in the range known to be suitable for wipes, typically in the range of from 15 to 300 gm/m² dry weight (although the material could have a higher basis weight if appropriate).

In some versions, an article in accordance with the invention could be packaged in an already moistened form so that it does not need to be moistened/dampened prior to use.

An example of a wiping article in accordance with the invention is a wipe comprising a latex-coated non-woven material, wherein the non-woven material is a carded, cross-lapped and needle-tacked material formed from a mixture of 75% by weight bamboo fibres and 25% by weight polyester fibres. The latex coating constitutes about 20% of the total weight of the wipe. In one version, the wipe has a basis weight of around 210 gm/m² and is intended for cleaning large surfaces such as floors (when it may be attached to a cleaning tool such as a mop). In another version, more suitable for cleaning smaller surfaces, the wipe has a basis weight of around 170 gm/m².

Another example of a wiping article in accordance with the invention is a thermo-bonded wipe, also of carded, cross-lapped and needle-tacked construction, which is formed from a mixture of 80% by weight bamboo fibres and 20% by weight thermo-bonding fibres. The thermo-bonding fibres are polypropylene fibres. As above, in one version, the wipe has a basis weight of around 210 gm/m² and, in another version, it has a basis weight of around 170 gm/m².

A further example of a wipe in accordance with the invention is a thermo-bonded wipe, also of carded, cross-lapped and needle-tacked construction, which is formed from a mixture of 75% by weight bamboo fibres, 15% polyester fibres and 10% by weight thermo-bonding fibres. The thermo-bonding fibres are polypropylene fibres. The wipe has a basis weight of around 210 gm/m².

Other wiping articles in accordance with the invention are described in greater detail in the following non-limiting examples. All parts and percentages quoted are by weight unless otherwise indicated.

The examples used the following materials, equipment and test methods:

Materials

Bamboo fibres: cut extruded fibres having a denier of 1.56 dtex and a length of 38 mm, commercially available from China Bambro Textile Co. of Beijing, China. Polyester fibres: denier and length similar to the bamboo fibres. Viscose fibres: denier and length similar to the bamboo fibres. Thermo-bonding fibres: polyester fibres available under the trade designation “MELTY” from Unitika Ltd. Of Osaka, Japan.

Equipment

Fiber opening and blending equipment: conventional equipment (available, for example, from MASIAS MAQUINARIA TEXTIL S.A. of Girona, Spain). Web-making apparatus: a conventional carding machine with feeder weight control (available, for example, from MASIAS MAQUINARIA TEXTIL S.A. of Girona, Spain) followed by a conventional cross lapping machine (available, for example, from AUTOMATEX NONWOVEN SRL of Pistoia, Italy) and a conventional needle tacker (available, for example, from FEHRER GmbH of Linz, Austria). Oven: a conventional oven (available, for example, from FLEISSNER GmbH of Egelsbach, Germany).

Test Methods

“Normal Domestic Use” Test: A wipe is subjected for a period of 10 days to the type of use normally encountered in a domestic kitchen (i.e. the wipe is used repeatedly in the course of each day in a wet/damp condition to clean domestic kitchen surfaces and, following each use, is rinsed in clean tap water and left until next required). The condition of the wipe is observed on a daily basis. Drying Test: A dry wipe is weighed, immersed in clean tap water, passed between the rollers of a mangle and weighed again. The wipe is then hung in a drying oven set at a temperature of 23° C., and weighed every 30 minutes. Measurement of bacterial contamination: A piece of a dry wipe was placed in a sterile bag to which a suspension of Salmonella typhimurium was added. The bag was squeezed repeatedly to distribute the suspension throughout the wipe sample, following which the bag was sealed and incubated at 20±2° C. Samples of suspension were withdrawn from the bag at intervals, and tested for bacterial contamination. The measurements were repeated using another piece of the dry wipe, without the bacterial contamination. Wipeability test: A dry wipe is immersed in clean tap water and then passed between the rollers of a mangle. A measured amount of water is placed on a test surface and wiped up with the damp wipe. The surface is then left to dry, and the time required for it to reach a dry state is recorded.

EXAMPLE 1

A thermo-bonded, carded and cross-lapped non-woven web material was formed using a fibre mixture comprising 75% bamboo fibre, 15% polyester fibre and 10% thermo-bonding fibres. The fibre bales were opened and the fibres blended in the required relative quantities before being fed to the web-making apparatus, in which a carded and cross-lapped, needle-tacked, non-woven web was formed in the conventional manner. The web was passed through the oven which was operated at a temperature sufficient to soften the thermo-bonding fibres and cause them to bond to the other fibres in the web, and thereby increase the stability of the latter. The web-making apparatus was operated to produce a non-woven web having a basis weight of about 150 μM/m². Wipe samples having a size of approximately 30 cm×30 cm were then cut from the non-woven web.

EXAMPLE 2

Example 1 was repeated except that the non-woven material was formed using a fibre mixture comprising 37.5% bamboo fibre, 37.5% viscose fibre, 15% polyester fibre and 10% thermo-bonding fibres.

EXAMPLE 3

Example 1 was repeated except that the non-woven material was formed using a fibre mixture comprising 75% viscose fibre, 15% polyester fibre and 10% thermo-bonding fibres.

EXAMPLE 4

Example 1 was repeated using, as samples, conventional thermobonded non-woven wipes comprising 60% cellulose fibers and 40% synthetic fibers, commercially available in Spain under the trade name “Ballerina” from Unilever.

EXAMPLE 5

A latex-coated web material was formed using a fibre mixture comprising 75% bamboo fibre and 25% polyester fibre. The fibre bales were opened and the fibres blended in the required relative quantities before being fed to the web-making apparatus, in which a carded and cross-lapped, needle-tacked, non-woven web was formed in the conventional manner. The web was then coated on both sides with latex and passed through the oven which was operated at a temperature sufficient to cure the latex coating. The finished web had a basis weight of about 210 gm/m², with the latex coating constituting about 20% of the total weight. Wipe samples having a size of approximately 30 cm×30 cm were then cut from the non-woven web.

EXAMPLE 6

Example 5 was repeated, except that the bamboo fibre was replaced by viscose fibre.

Results

The wipe samples of Examples 1 and 3 were subjected to the “Normal Domestic Use” Test, and the samples of Examples 1 to 4 were subjected to the Drying Test described above. Measurements of bacterial contamination were carried out as described above on samples of Examples 1 and 3, and the samples of Examples 5 and 6 were subjected to the Wipeability Test.

During the “Normal Domestic Use” Test, the samples of Example 3 (which contained no bamboo fibres) were observed to develop an unpleasant odour and an unpleasant slimy feel after only a few days whereas the samples of Example 1 remained free of such effects for the whole duration of the test. The absorption properties of all of the samples appeared to be similar, as did the wipeability (i.e. the measure of the time taken for a wiped surface to dry).

The results of the Drying Test are summarized in the accompanying FIG. 1, which is a chart illustrating the average amount of water retained by the four categories of wipe samples as a function of time in the drying oven. The amount of water retained by each category of samples is indicated by the average weight of the samples at a particular time, expressed as a percentage of their dry weight. The chart shows that the samples of Example 1 were substantially dry after a period of 90 minutes in the drying oven whereas the samples of Examples 3 and 4 (which contained no bamboo fibres) required almost another hour to reach a similar state. The samples of Example 2 dried more quickly than those of Examples 3 and 4, especially at the beginning of the Test, although more slowly than those of Example 1.

The measurement of bacterial contamination showed that samples of Example 1 possessed bacteriostatic properties when subjected to contamination by Salmonella typhimurium in that growth of the bacteria ceased after 3 days. No such properties were observed in samples of Example 3. The measurements also showed that uncontaminated samples of Example 1 possessed some resistance to natural bacterial contamination in that contamination of the samples remained comparatively low over a period of 7 days. Natural contamination of the samples of Example 3, on the other hand, increased noticeably over the same period.

The Wipeability test, when carried out using a mirror as the test surface, showed that the surface dried in about 60 seconds when wiped with samples of Example 5 compared with about 110 seconds when wiped in a similar manner with samples of Example 6. When carried out using a terrazzo floor as the test surface and, for the area involved, a relatively smaller amount of water more evenly distributed over the surface, the test showed that the surface dried in about 10 minutes when wiped with samples of Example 5 compared with about 14 minutes when wiped in a similar manner with samples of Example 6.

CONCLUSIONS

The tests show that the inclusion of bamboo fibres in thermobonded non-woven wipes that are intended to be used in a damp/wet condition results in the wipes remaining in a pleasant-to-use and hygienic condition for substantially longer than equivalent conventional wipes that do not contain bamboo fibres. They can also be dried more quickly after use, making them more attractive to the user and also helping to reduce the development of bad odours and any slimy feel. The tests also show that the inclusion of the bamboo fibres had a beneficial effect on the contamination of the wipes by Salmonella typhimurium. It is expected that similar effects will be observed in other wipes incorporating bamboo fibres, including those of a knitted or woven construction.

The tests also show that the inclusion of bamboo fibres in latex-coated non-woven wipes had a beneficial effect on their “wipeability”.

Wipes in accordance with the invention as described above constitute, in themselves, articles for the wet/damp wiping of surfaces. In that case, both surfaces of a wipe provide a wiping action. Typically, both surfaces of the wipe will provide the same wiping action but that is not necessarily always the case: through modification of the web-making process, or subsequent treatment of the finished web, the two sides of a wipe may differ, for example, in terms of their absorption characteristics or their abrasive natures.

Alternatively, a wipe in accordance with the invention as described above may be bonded to another material to provide an article for the wet/damp wiping of surfaces. The second material may simply provide a support for the wipe but, more usually, will be another material suitable for use in cleaning surfaces (for example, a material that provides a different wiping action). The two materials may be laminated together, for example by means of a suitable adhesive. The second material may, for example, be formed from a textile material, a sponge material or a sponge-cloth material. Alternatively, the second material may be a non-woven abrasive material. 

1-14. (canceled)
 15. An article for the wet/damp wiping of surfaces, the article comprising a moisture-absorbing wipe that provides at least one surface of the article, wherein the wipe comprises bamboo fibers.
 16. An article as claimed in claim 15, in which the wipe comprises at least 10%, preferably at least 30%, by weight of bamboo fibers.
 17. An article as claimed in claim 15, in which the wipe is formed into a textile material.
 18. An article as claimed in claim 17, in which the textile material is a non-woven material.
 19. An article as claimed in claim 18, in which the non-woven material is selected from the group consisting of spun lace materials; carded, cross-lapped and needle-tacked materials; and thermo-bonded materials.
 20. An article as claimed in claim 18, in which the non-woven material is a latex-coated material.
 21. An article as claimed in claim 17, in which the textile material is a knitted or a woven material.
 22. An article as claimed in claim 17, in which the textile material has a basis weight in the range of from 15 to 300 gm/m².
 23. An article as claimed in claim 17, in which the textile material further comprises fibers selected from other natural fibers or fibers/microfibers of viscose, polyester, polyamide, polypropylene, PVA or mixtures thereof.
 24. An article as claimed in claim 1, in which the wipe is bonded to another material.
 25. An article as claimed in claim 24, in which the other material is a textile material, a sponge material or a sponge-cloth material.
 26. An article as claimed in claim 1, the article being packaged in a pre-moistened condition. 